Sure, mistakes happen, but this is the first such in Academy history. The closest to this was when Sammy Davis, Jr. read the wrong name in the sixties, which was for a different music category he was also to give. He made a joke about reporting it to the NAACP. But the name he gave was in fact a winner later on. In this case, it was horrific, and I feel for the La La Land people, even as the Moonlight people clearly had mixed reactions with their win.
Oscar Stunner — How Pleasant Run of the Mill Show Turned Into Nightmare For Announced Winner – Huffington Post